Prevent WooCommerce checkout if minimum quantity for a specific category is not reached

Question

I have some cart logic which checks for a minimum of 3 items if 1 item from the chilled category is in the cart. - This is tested and working.

However, if I add another item to the cart from a different category (ambient), and there are now both chilled and ambient items in the cart, the rule is no longer applied.

How can I make sure the 3 chilled minimum rule is applied if an ambient item is also in the cart?

// Set minimum quantity per product before checking out
add_action( 'woocommerce_check_cart_items', 'protein_set_min_total' );
    function protein_set_min_total() {
        // Only run in the Cart or Checkout pages
        if( is_cart() || is_checkout() ) {

            global $woocommerce, $product;
            $i=0;
          
            // Set minimum product cart total
            //And initialise product catergory counters
            $minimum_protein = 3;
            $total_protein = 0;
            $cat_in_cart = false;

            foreach ( $woocommerce->cart->cart_contents as $product ) :
                if ( has_term( 'chilled', 'product_cat', $product['product_id'] ) ) {
                   $total_protein += $product['quantity'];
                }
            endforeach;
          
            if (has_term( 'chilled', 'product_cat', $product['product_id'] ) && $total_protein < $minimum_protein) {
                wc_add_notice( sprintf( '<strong>A Minimum of %s products are required from The CHILLED category before checking out.</strong>'
                . '<br />Current number of Chilled items in the cart: %s.',
                    $minimum_protein,
                    $total_protein ),
                'error' );
            }
        //}
    }
}

Answer 1

The code below will count all items belonging to the chilled category. Only if this is equal to 3 or more, will it be possible to continue the order process.

So you get:

function action_woocommerce_check_cart_items() {
    // Only run on the cart or checkout pages
    if ( is_cart() || is_checkout() ) {     
        // Minimum
        $minimum = 3;
        
        // Category
        $category = 'chilled';
        
        // Initialize
        $total = 0;
        
        // Loop through cart items        
        foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {        
            // Product id
            $product_id = $cart_item['product_id'];

            // Has certain category
            if ( has_term( $category, 'product_cat', $product_id ) ) {              
                // Add to total
                $total += $cart_item['quantity'];
            }
        }
        
        // When total is greater than 0 but less than the minimum
        if ( $total > 0 && $total < $minimum ) {
            // Notice
            wc_add_notice( sprintf( __( 'A minimum of %s products are required from the %s category before checking out.', 'woocommerce' ), $minimum, $category ), 'error' );
            
            // Optional: remove proceed to checkout button
            remove_action( 'woocommerce_proceed_to_checkout', 'woocommerce_button_proceed_to_checkout', 20 );
        }
    }
}   
add_action( 'woocommerce_check_cart_items' , 'action_woocommerce_check_cart_items', 10, 0 );